org.thales.punch.libraries.storm.spout.impl

Class LogFileTailer

java.lang.Object

java.lang.Thread

org.thales.punch.libraries.storm.spout.impl.LogFileTailer

All Implemented Interfaces:

Runnable

public class LogFileTailer
extends Thread

A log file tailer is designed to monitor a log file and send notifications when new lines are added to the log file. This class has a notification strategy similar to a SAX parser: implement the LogFileTailerListener interface, create a LogFileTailer to tail your log file, add yourself as a listener, and start the LogFileTailer. It is your job to interpret the results, build meaningful sets of data, etc. This tailer simply fires notifications containing new log file lines, one at a time.

This said you can also use the file tailer to read a file just once and exit. Use the doNotTail method to make it work that way.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor and Description
LogFileTailer(org.thales.punch.settings.api.ISettingsMap settings, org.apache.logging.log4j.Logger logger, File file, long readInterval, boolean startFromBeginning) Creates a new log file tailer

Method Summary

Modifier and Type	Method and Description
LogFileTailer	addLogFileTailerListener(LogFileTailerListener l) add a listener
protected void	fireNewLogFileLine(String line, Map<String,String> properties)
org.thales.punch.punchlang.util.ICodec<String>	getCodec(org.thales.punch.settings.api.ISettingsMap settings) Build specific codec from config
void	readFile() Use this method to read a file in a synchronous way.
LogFileTailer	removeLogFileTailerListener(LogFileTailerListener l) remove a listener
void	run()
LogFileTailer	setTailling(boolean t) enable/disable file tailing
void	tick() Flush buffer after timeout, tick is only implement for multiline codec

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

LogFileTailer

public LogFileTailer(org.thales.punch.settings.api.ISettingsMap settings,
                     org.apache.logging.log4j.Logger logger,
                     File file,
                     long readInterval,
                     boolean startFromBeginning)

Creates a new log file tailer

Parameters:

settings - Spout settings to get codec type

logger - Log

file - The file to tail

readInterval - Check interval for updates to the log file in ms

startFromBeginning - Should the tailer simply tail or should it process the entire file and continue tailing (true) or simply start tailing from the end of the file

Method Detail

setTailling

public LogFileTailer setTailling(boolean t)

enable/disable file tailing

Parameters:

t - boolean

Returns:

this instance

addLogFileTailerListener

public LogFileTailer addLogFileTailerListener(LogFileTailerListener l)

add a listener

Parameters:

l - the listener

Returns:

this instance

removeLogFileTailerListener

public LogFileTailer removeLogFileTailerListener(LogFileTailerListener l)

remove a listener

Parameters:

l - the listener

Returns:

this instance

fireNewLogFileLine

protected void fireNewLogFileLine(String line,
                                  Map<String,String> properties)

readFile

public void readFile()

Use this method to read a file in a synchronous way. This method automatically is called by the run() when a LogFileTailer thread is started (i.e. with Thread.start()) when we want to read it in an async way..

tick

public void tick()

Flush buffer after timeout, tick is only implement for multiline codec

getCodec

public org.thales.punch.punchlang.util.ICodec<String> getCodec(org.thales.punch.settings.api.ISettingsMap settings)

Build specific codec from config

Parameters:

settings - the settings map with host port properties

Returns:

codec

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread